Apparatus, method and program for segmentation of mesh model data into analytic surfaces based on robust curvature estimation and region growing

Abstract

An apparatus, a method and a program segment mesh model data into analytic surfaces based on robust curvature estimation and region growing by extracting, from mesh model data, analytic surface regions (planar, cylindrical, conical, spherical and toric surface regions) and by automatically recognizing fillet surface regions, linear-extrusion surface regions and surface regions of revolution from the extracted regions and edges. The apparatus, method and program input mesh model data, find sharp vertices in the mesh model data, calculate principal curvatures at each non-sharp vertex, create, from the calculated principal curvatures, seed regions each being considered to belong to an analytic surface region and including a set of linked vertices, extract analytic surface regions by growing the seed regions, recognize fillet surface regions, linear-extrusion surface regions and surface regions of revolution in the extracted analytic surface regions, and output information concerning the extracted analytic surface regions and information concerning the recognized regions.

Description

CORRESPONDING PATENT APPLICATION [0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2006-035719 which was filed on Feb. 13, 2006. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an apparatus, a method and a program for segmentation of mesh model data into analytic surfaces based on robust curvature estimation and region growing. [0004] 2. Description of Related Art [0005] 3D laser scanning systems are widely used in the field of reverse engineering to acquire geometric point cloud data from real-world products. More recently, high energy X-ray scanning systems have been rapidly developed, and they are used to acquire 3D image data of complex engineering parts with inner structures quickly and non-destructively. To use the acquired scanned data in today's digital engineering, it is easily converted into a 3D mesh model by a well known surface reconstruction algori...

AI Technical Summary

Benefits of technology

[0035] An object of the present invention is to provide an apparatus, a method and a program for segmentation of mesh model data into analytic surfaces based on robust curvature estimation and region growing that segments mesh model data into regions where each can be approximated by a simple analytic surface. The present invention employs an accurate mesh curvature estimation based on recognition of sharp edges on a noisy mesh model. Combining this accurate curvature estimation with the non-iterative region growing enables to find more accurate boundaries between underlying analytic surfaces. Moreover, the present invention can extract higher-level classes of surfaces (fillet surfaces, linear extrusion surfaces and surfaces of revolution) from the analytic surfaces by categorizing neighboring relations of surfaces and by grouping them.

[0055] In this way, the apparatus, method and program according to the present invention are capable of inputting a mesh model prepared from a machine part, extracting, from the mesh model, analytic surface regions (planar, cylindrical, conical, spherical and toric surface regions), and automatically recognizing fillet surface regions, linear-extrusion surface regions and surface regions of revolution from the extracted analytic surface regions.

Problems solved by technology

Moreover, in these methods, the accuracies of extracting regions from noisy mesh models and the range of extracted analytic surface classes were not necessarily sufficient from the aspect of practical engineering use.

However they cannot extract regions separated by smooth edges (i.e., a region consisting of a plane smoothly connected to a cylinder), and therefore cannot correctly identify the surface geometry of each segmented region.

However the method did not focus on extracting regions approximated by analytic surfaces and their geometric parameters.

However this method only extracts regions which can be approximated by planes, cylinders and spheres.

However they did not discuss how well the method works for a noisy mesh model, and how they specify initial regions of segmentation.

Moreover the processing time is relatively slow due to the iteration of surface fitting and clustering.

However this algorithm can result in poor segmentation near boundaries of surfaces where the indicators in mesh models may not be properly estimated.

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